Distinct Viscoelasticity of Nanoparticle-Tethering Polymers Revealed by Nonequilibrium Molecular Dynamics Simulations

We employed nonequilibrium molecular dynamics simulations to study viscoelastic properties of nano particle-tethering polymers. Effects of nanoparticle-polymer interaction and molecular architecture on the viscoelasticity are investigated. The results show that the nanoparticle-tethering polymers with attractive nanoparticle-polymer interaction exhibit enhanced storage and loss moduli relative to the homopolymers or bare nanoparticle/polymer blend. In addition, the storage and loss moduli of nanoparticle-tethering polymers can be further enhanced through tuning their molecular architectures, such as increasing the nanoparticle diameter or decreasing the polymer chain length: From the physical origin, the enhancement of dynamic moduli originates from the slowdown of polymer dynamics, which arises from the attractive nanoparticle-polymer interaction, the tethering covalent bond, and the obstacle of nanoparticles. The present work not only reveals the physical origin of distinct viscoelasticity of nanoparticle-tethering polymers, but also provides useful information for preparing advanced materials based on these organic/inorganic components.